Plowshare



May 24, 1949.

T. MGHL 2,471,164

PLOWSHARE Filed Julie 26, 1941 Patented May 24, 1949 PLOWSHARE Torben Miihl, Copenhagen, Denmark; vested in the Attorney General of the United States Application June 26, 1941, Serial No. 399,875 In Denmark June 11, 1940 Sections 1, 3, 14, Public Law 690, August 8, 1946 Patent expires June 11, 1960 1 Claim. (01. 97 125) This invention relates to a plough share.

As is well known, the commonly employed plough shares consist either of a very heavy and accordingly rigid plate having a sharpened leading edge, or of one or more thinner plates-the so called self-sharpening shares-having ribs, beads or bent edges for reinforcing the share at such places, particularly at the plough tip which are exposed to breakage in use. These reinforcements, however, require that the reinforced portions of the share shall be rigid and are therefore easily subjected to breakage during use by striking stones or other obstacles, and further these shareslike the first named shareswi1l contain a considerable quantity of material after the share has become worn and must be replaced by a new one. Accordingly, a rather considerable quantity of material is lost. Also, plough shares having reinforcing ribs, beads or bent land side edges are expensive to produce because they necessitate the use of special machinery for their production.

In order to reduce the quantity of material in a plough share it has been proposed to manufacture the share of a relatively thin share plate and a narrower reinforcing plate arranged at the under side of the share plate and produced from relatively soft material, andin order to obtain suf icient rigidity of the plough tip of such a share, being integral with the share plate-to bend the edge of the share plate lying in the land side. However, such shares are liable to deformation by striking stones or like obstacles, and, like the shares mentioned above, they suffer from the drawback that their capacity, i. e. their tendency to dig into the ground when ploughing, varies from hard, heavy soil to soft soil. Another disadvantage of these shares is that wear makes the reinforcement dull and therefore no longer sharp.

The present invention has for its purpose to provide a plough share which obviates the above named drawbacks of the previously known plough shares and which-like some of the known oneswill remain sharp until it is practically worn out.

More particularly my invention has for its purpose to provide a share that is cheap and very resistive to breakage and bending stresses in use and the replacement by a new one will cause a considerable less loss of material than with the previously known shares, and the ability to maintain a uniform depth in the soil during ploughing is considerably greater than that of the previously known shares.

With these and other objects in mind, according to the invention the plough share is made resilient, being made from two or more layers of relatively thin steel plates of uniform thickness without bent edges, ribs or beads for reinforcing the share, and the width of these plates measured from the trailing edge of the share to the leading edge of each individual plate is of unequal value and in such a manner that the width decreases from the uppermost to the lowermost of the plate layers lying tight together and held together by means of fastening bolts of the plough share. By this arrangement there is obtained the advantage that the plough share, and in particular the projecting plough tip constituted in known manner by an integral part of the uppermost plate, will have a rather considerable resiliency so that, when, e. g. striking a stone, it will yield and thereby to a very considerable degree reduce the danger of deformation of the plough share As a result of the resiliency of the plough share and particularly the tip thereof the share will tend to dig in deeper when ploughing in hard and heavy soil than when ploughing in loose soil, because under the influence of resistance of the soil the share tip is subjected to a greater or smaller, non-permanent deflection according as it works in harder or softer soil and will therefore have more tendency to dig into the soil the harder the latter. This increase of the ground digging ability when working in hard soil will counteract the well known tendency of the plough share, from other causes, to dig the less into the soil the harder the latter. By suitable adjustment of the share tip it will, therefore, be possible to Work at a more uniform depth in the soil than With known shares, irrespective of the quality of the soil.

I am aware that it is known to provide a plough share of two plates one above the other to be interexchanged so that sometimes one and sometimes the other of these plates may be used as the share plate. These plates, however, are provided with reinforcing ribs and therefore have substantially the same drawbacks as the known plough shares mentioned above.

As mentioned, the uppermost plate of a plough share according to the invention constitutes the proper share plate while the other layers of the share substantially serve to support and resiliently reinforce the share plate. When the share plate is worn down substantially to the leading edge of the adjacent share plate, it is replaced by a new one but it is not necessary therefore also to replace the reinforcing plates. Hereby the advantage is attained that the quantity of share material lost when replacing the share is only a fraction of the waste material when replacing the known shares.

understood reference will now ldetmadeto-the accompanying drawing illustrating, by-way"oiarr example only, an embodimenttofimyl inventioni. Fig. 1 being .a plan view of the plough share" from below, and

Fig. 2 a section through sameorr therlinel-I in Fig. 1.

a, b and c are three plates made fromaspriilg steel having a uniform thickness of, e. g. 3 to 5 mm.', .andias is apparent; fromifig 2;,having unequal widths-,-:.thempnermostaplatea having a-.oonsiderably greater. width than: the: intermediate plate b, andither latter :in .itsrturn. havinga some what greater width than; theelowermostiplate: At one side lthe uppermostplater is-iiormedswith a tipd,.the-plough tip: The-leading edgesiwflb and. c'- of the plates-:ara'sliarpenedland,,onaccount of: the unequal: widths: 0.5: thalplatesiwill lie indifferent:distances;fromithestrailingyedge-e ofthe share; this: arrangement is: attained that. the share;- will; yield: I'BSiliBhtlYE-ini similar manner as: a: multllayierr carriage sprine-z-when Working in the:.-so.i-l,' andzlnarticularlyg'theaplough tip will be very resilient'zandtwill.athereforepbezable to yieldito istones. 301! likezohstaclesrso thatthezrisk of breakage and deformations; of the plough shares in use is;reducedattnaimlnimmnr.

The three l-platesiarerheldltogetherrbyimeans 501 two bolts 1. servingzirrlknowmmannerz'fon the: at; tachment-ofi'the 'shareztozthea -mouldiplate Ofthe plough;

As is apparentz-fromtEige; 1i ,therplateswlnandi 0 also have a: somewhat: projecting". lug: gt; andi h respectivelyuin': theiland-sida; ofiltherplough; these lugsextendingatowardsntha!ploughntimandtaresili ently supportinggsames. The 'leadcing'cedges ofthe platesib; and .candzthercorrespondingalugs grand h are preferably: shaped: acording-r tor such: curves asxjthe share:platens:linowrrltoctenditowfollow in proportion torwear; By thisimeans 115 i attained thatthe share platemnnayiheiwormapproximatelyto the leading; edger-.offthceplate'ab; and that; if desired, the plater:bomayytliemheeremoved; and the share: employed: with tlietplate w as. share plateand-.l'thezplate ccas resilientisupporting:plate for the .same; .amarrompl atewstripxof isam e thickness as the platexbzbeirxgxthen"arranged-in place of the: one: on; the: plate? 6* along: the? bolts f in order; to facilitate; tightening; bw' means of" the b01ts:.f.. The-.removedzplatev bflisakept ready'for use, when the share plata aci'sireplacediby a new 4 plate. In this manner the material of the share may be utilized in a very economical manner.

Even if the share plate a is only employed until worn approximately to the leading edge of the plate I], or more correctly, approximately to the position indicated by the dotted linevk; the quantity of share material not used again; when the plate is replaced by a new one, will only be a relatively small fraction of the total quantity of share material, as a rule between 30 and 35%, while with the previously known shares the quantity of-lost 'material-will lie between '75 and As-isapparent from Fig. 2, the leading edges of. the plates a, b and c are sharp. The leading edgelofl the plate a will, on account of its small thickness, keep sharp, until the plate is prac: tically worn out.

In order to avoid penetration of earth between the: plates a and b at the land side of the share, it will be advantageous t connect the lug g of the plate b'withthe. plate a.- by; means; oflarivet I, Fig; 1,.for. instance of.soft iron, extending through thetwoplates. The. diameter. of. thehole, in whichithisrivet is placed, may,- suitably. be made slightly. greater. than the. diameter. of. the rivet, so. that the rivet .will noti injure? the ,-resiliency of the share.

Having. now particularly: described: and ascertained the nature of-myinvention-and in what manner the same. is to. be performed; I- declare that what I-claim. is:.

A. plough share composed of two.- or-. more lay-- ers of relatively-- thin: steel, plates; of. which. the uppermost. plateconstitutes; the. proper. share plate and i also the plough :tip of; theshare; characterized inthat ea'chlayerl of-the plough share consistsof a. planeor: slightly, arcuate; hardened steel plate of uniforn'rv thickness, and, that the widthsof these plates measured'r'from the trailing edge. of the share to. the, leading edge of each plate is of unequal value-.and: decreases from the uppermost .to the lowermostv of 1 the-p1atelayers, said.- plate. layers being. secured adjacent each other, whereby theploughishare, andr theprojecting plough tip-oi: theluppermost plate, are given a. considerable resiliency.

TQRB NMHL.

REFERENCES.- CIIITEDv The following: ref erences: areof record in' the file: of'this patent? UNITED. STATES PATENTS' Number Name Date 302,027 Eugh .J'uly15, 1884 835,007 Bippart .N-ov. 13; 1906 FOREIGNPATENTS" Number. Country Date;

33,318. Denmark. .May-. 22, 1924 518,971 Germany .Feb. 21; 1931 

